IB: Fix RCU lockdep splats
Commit f2c31e32b37 ("net: fix NULL dereferences in check_peer_redir()")
forgot to take care of infiniband uses of dst neighbours.
Many thanks to Marc Aurele who provided a nice bug report and feedback.
Reported-by: Marc Aurele La France <tsi@ualberta.ca>
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Cc: David Miller <davem@davemloft.net>
Cc: <stable@kernel.org>
Signed-off-by: Roland Dreier <roland@purestorage.com>
diff --git a/drivers/infiniband/hw/cxgb4/cm.c b/drivers/infiniband/hw/cxgb4/cm.c
index b36cdac..75b57bee 100644
--- a/drivers/infiniband/hw/cxgb4/cm.c
+++ b/drivers/infiniband/hw/cxgb4/cm.c
@@ -1594,6 +1594,7 @@
goto reject;
}
dst = &rt->dst;
+ rcu_read_lock();
neigh = dst_get_neighbour(dst);
if (neigh->dev->flags & IFF_LOOPBACK) {
pdev = ip_dev_find(&init_net, peer_ip);
@@ -1620,6 +1621,7 @@
rss_qid = dev->rdev.lldi.rxq_ids[
cxgb4_port_idx(neigh->dev) * step];
}
+ rcu_read_unlock();
if (!l2t) {
printk(KERN_ERR MOD "%s - failed to allocate l2t entry!\n",
__func__);
@@ -1820,6 +1822,7 @@
}
ep->dst = &rt->dst;
+ rcu_read_lock();
neigh = dst_get_neighbour(ep->dst);
/* get a l2t entry */
@@ -1856,6 +1859,7 @@
ep->rss_qid = ep->com.dev->rdev.lldi.rxq_ids[
cxgb4_port_idx(neigh->dev) * step];
}
+ rcu_read_unlock();
if (!ep->l2t) {
printk(KERN_ERR MOD "%s - cannot alloc l2e.\n", __func__);
err = -ENOMEM;
@@ -2301,6 +2305,7 @@
}
ep->dst = &rt->dst;
+ rcu_read_lock();
neigh = dst_get_neighbour(ep->dst);
/* get a l2t entry */
@@ -2339,6 +2344,7 @@
ep->retry_with_mpa_v1 = 0;
ep->tried_with_mpa_v1 = 0;
}
+ rcu_read_unlock();
if (!ep->l2t) {
printk(KERN_ERR MOD "%s - cannot alloc l2e.\n", __func__);
err = -ENOMEM;